Justification:Acianthera variegata is an epiphytic orchid, which is reported to occur in Minas Gerais and Rio de Janeiro in Brazil, from two localities some 300 km apart. Acianthera variegata has not been collected since 1948. It is not known whether this orchid still occurs in these two localities. The Atlantic Forest has been reduced to 8% of its original area. Remains are mostly dissected in tiny and widely separated forest fragments. In Mata Atlantica, the fact that many epiphytes are known from only one population is not due to uneven sampling effort but because they represent the last remain of an earlier biodiversity (Filho and Leme 2006). Surveys and censuses should be conducted in Macae the Cima and surrounding fragments of montane Atlantic forests and forests fragments around Caldas, in Minas Gerais to determine whether A. variegata is still extant and whether local extinction has occurred. These surveys should allow to clarify the current conservation status of this elusive orchid. To the present knowledge, a rating of Endangered is given to A. variegata as it is known from two locations, with EOO and AOO which are less than 5,000 and 500 km2 respectively, and there are known threats to this fragmented habitat.

This species is an epiphytic orchid, which is reported to occur in Minas Gerais (Govaerts 2004) and Rio de Janeiro (specimen data, Rio de Janeiro Herbarium), in Brazil, from two localities some 300 km apart.

This species is only known from three collections, treated as two localities. The taxon was collected twice in Macae de Cima, Rio de Janeiro around 1948 and the type was collected prior to 1896, by Rodrigues, in Caldas, Minas Gerais. It has not been collected since. It is not known whether this orchid still occurs in these two localities. It was not found in the orchid survey of the floristic reserve of Macae de Cima (Miller and Warren 1996). The size and dynamics of the population, if still extant, are unknown.

There is no other information on the type of habitats in which this species was collected. The altitude at both localities is ca 1,200 m asl. In Minas Gerais, the orchid was collected by a river and may have occurred in gallery forest. One collection was made within the Campos Rupestre Montane Savanna Ecoregion and the other one within the Serra do Mar Coastal Forests Ecoregion (GIS data).

Epiphytes have experienced dramatic population decreases mainly because of habitat loss and extraction activities, which have driven many species close to extinction (Mondragon et al. 2006). Since the 16th century, the Atlantic rainforest, a biodiversity hotspot (Myers et al. 2000), has suffered from uninterrupted deforestation and has been reduced to 8% of its original area. Remains are mostly dissected in tiny and widely separated forest fragments. Natural habitats in the localities of collection seems to have been highly converted, altered and degraded into a mosaic of cropland, pastures, and shrubland (GIS data), with medium to high human footprint (Sanderson et al. 2002). The Serra do Mar forests have been reduced in area by 53%. Natural habitats within the Campos Rupestre have also been largely altered. Besides ongoing conversion of forest for agriculture, pasture and urban expansion, other threats to epiphytic orchids in the region include mining, tourism, the harvesting of firewood, illegal logging, plant collecting, invasion by alien species and lianas, air pollution, and fires. Forest fragmentation directly threaten epiphytic orchids through the loss of porophytes, pollinators, increased desiccation and risks of fires, invasion of ruderal plants and also facilitates extractivism of ornamental species (Da Silva 2001, Maria 2001, Filho and Leme 2006). The ability of this species to regenerate and persist in disturbed and secondary forests is unknown.It may have been or be the prey of unscrupulous collectors. Collecting orchids from natural sources is still very common in Brazil in spite of prohibitions of international commerce of species collected in the wild (Appendix II of the Convention on International Trade in Endangered Species – CITES) (Saddi et al. 2005).

One collection was made within the within the Reserva Ecológica de Macaé de Cima, the second biggest area of the Atlantic Forest in the state of Rio de Janeiro, while natural habitats in the other locality of collection, in Minas Gerais do not currently benefit from any protection. The Serra do Mar Corridor is currently being implemented as part of the PP-G7 Atlantic forest subprogram (Tabarelli et al. 2005) and Unesco Biosphere Reserve of Mata Atlantica development. Many forest fragments occur on private land and innovative incentives are needed. Extensive habitat restoration and expansion of protected areas is needed for the establishment of corridors (Filho and Leme 2006). This orchid is currently listed on Appendix II of the Convention on International Trade in Endangered Species (CITES). The species is not grown within any botanical institutions.

Surveys and census should be conducted in Macae the Cima and surrounding fragments of montane Atlantic forests and forests fragments around Caldas, in Minas Gerais to determine whether the taxon is still extant and whether local extinction has occurred. Micropropagation protocols should be designed for population reinforcement, for in vitro preservation and to alleviate the potential pressure of extraction on the wild population. If possible, seed should be collected and stored for germplasm conservation. Raising awareness on the risk of extinction face by these epiphytic orchids is important.